Spark-plug.



W. REPPIN.

SPARK PLUG.

APPLICATION FILED vNOV. 2l, |913 RENEWED NOVl I6. |917.

MWAW., I A j Pafentmune 25, 1918.

i annV en.-

wnErEE EErrrn, or NEWARK, nEw .rEEsEr intentar,

citizen of the United city of Newark, in the county of lEsseX and llt - resistance of the circuit,

lwhose combined length Specification of Letters Patent.

Patented all' une 25, ferie.

Application led November 21, 1 9113,.Seria1 No. 302,193. Renewed November 16, 191'?. Serial No. 202,426.

.To all whom it may concern:

Be it known that l, WALTER REPPIN, a States, residing in the State' of New Jersey, have invented certain new and useful Improvements in Spark- Plugs, of which .the following is a full, clear, and exact description, such as will enable :1v others skilled in the art to which it pertains 'tu to make, construct, and use the same, reference being had to the accompanying drawings, 'and to numerals of reference marked thereon, forming a part of this specification.

rlShis invention relates to improvements in electric sparking devices, particularly spark plugs for use for igniting the explosive gases in the cylinders in internal combustion en gines, andthe said invention consists in the construction, combination and arrangements vofwparts hereinafter shown ,and described.

The object of this invention is to prevent short circuiting of spark plugs, by employing a series of electrodes insulated in a manner to form a series of gaps for the passage of the electrical spark. 'llhese electrodes may `be readily mounted upon an insulating core or within a suitable recess formed in the end of the insulating core. s

lt is well known that the heat value of the current is inversely proportional to the and by introducing electrodes in series, the resistance of the circuit is much less than the resistance of a gap, would be equal to the sum of all the gaps, and by thus having lowered the resistancegreater amount of current is utilized in pro- .ducing a spark',.and for this reason,.the

" spark vwould be hotter.

l erably in the nature of Heretofore, it` has' beenI customary to employ a single spark gap, or anumber of spark gaps, but in such a manner that if A p one of these gaps shouldbecome'short'circuited, eitherby oil, carbon,

or otherwise, there would be no sparkat any ofthe gaps, whereas. in the construction of my plug, if one or more electrodes should become shortcircuited, the remainin gaps would produce a more intense spark ecause of the lower ,A

resistance in thecircuit.

'llhe electrodes which I employ-are prefopen rings, which facilitate the ready mounting or assembling lthereof on the insulating core, and although of the circuit, a

may be desirable, l find that in the use of open rings, as shown in the accompanying drawings, where the plug is eXposed to the action of oil, the same form a ready means for permitting any surplus of oil which might have a tendency to adhere to the plug to be discharged therefrom.

lin the preferred form of my invention, l have shown the metallic base which is screwed into the motor cylinder, provided with an annular recess or cavity extending over the series ofelectrodes in such a manner as to confine the sparks and intensify the same, by virtue of the metallic shell inclosing the sparks, thus producing a solid flame,

' and also to prevent as far as possible, the

ingress of oil upon the central core and the series of electrodes.

lt is also known that the accumulation of unconsumed oil in the cylinder is the cause of carbonization, and if for plug becomes short-circuited, this oil cannot' be consumed, and quickly carbonizes.

to the intensity of ignite a weaker tion of a sparkplug embodying my inven- -tion in its preferred lform.

this spark plug re- 1 any reason the get increased eliiciency I WML..

Flg. 2 represents a side elevation rof the centrally bored'. insulating core removed from ythe plug, provided with a central electrode'and a plurality. of electrodes.

lll@

Fig. 3, represents a similar view, partly in section ,of a modified form of ing core. y

Figs.v 4 and 6 represents plan views of the the insulatpreferred forms of electrodes to be usedin connection with my improved device.

Fig. 5 represents a plan view of a pre-l filmt A Suitable material, surrounded by ferred form of washer to be used in connection with my improved device; and

Figs. 7 and 8 represent fragmentary views of modified forms of insulating cores, a provided with a plurality of electrodes. j Similar numerals of reference indicate corresponding parts throughout the specification and drawings.

So far as the general construction of the no plug is concerned, it may be of any desired form or structure. j

y In the present instance, it is illustrated as comprising a centrally bored insulating core `1, which may be of mica, porcelain, or other j, a chambered casing 2 which is externally threaded, as at 3, 'for connection with, the apparatus or engine in which it is to be used, and internally threaded as at 4, for the reception of an exteriorly threaded nut 5, by meansy of which the insulating body or core and the casing 2 are firmly secured together. l

A suitable washer or packing 6 may be used between the shoulder 7 of the insulating core 1 and the shoulder 8 of the casing 2. Extending through the insulating body .1 is the electrode 9, which is provided with an enlargedlhead 10, between which and the insulating bodyis located a suitable washer e0 11, provided with two diametrically-oppositely arranged projections 12, as clearly illustrated in Fig. 5 of the drawings, and

which electrode lis secured -in position by means of the usual nuts 13 and 14, turned on tween which nuts and the insulating body, is also located a suitable washer 15.

surplus of oil which might have a tendency to adhere to the plug, to be discharged therefrom.

The chambered casing 2 after the insulating core has been secured therein, forms an annular cavity 19, surroundin the electrodes in such a manner as to con ne the sparks and intensify the same, by virtue of the chambered casin inclosing the sparks, thus producing a soli llame, and also preventing as far as possible, the ingress of oil upon the central core and electrodes.

In Fig. 3 of the drawings, I have shown the insulating core provided with preferably a tapered recess provided with a'series of grooves, into which the electrodes, in the na-.

a5 they threaded end, of the electrode and be- Theinsulating body 1 is provided with a reduced portion l16, projecting an appreciaa@ ble distance inside the end of the chambered casing 2, having formed thereon, a plurality of preferablyzparallel grooves,`in this case, four in number, although any convenient number may be employed, into which are e5 sprung the electrodes 17, referably made of ordinary steel wire, the rst three of which are inthe nature of open rings, 4as illustrated in Fig. 4 of the drawings, and the last electrode is preferably l made with a projecting end 18,. as illustrated' in Fig. 6 ofith drawings, designed to be grounded in theA chambered casing 2, as clearly indicated in Fig. 1 of the drawings. It will thus be seen that by mounting the e5 washer 11 and a number of electrodes 17 on the insulating core, vsaid electrodes being insul'ated'from each other, a series of small,` uniform gaps from the central electrode to thecasing 2 are formed. By the employ- @o ment* of open rings, the ready mountingor assembling of the electrodes on the insulat` ing core is greatly facilitated, and 'furthermore, the use of open rings; particularly where the plug' is exposed to the action of oil, forma lready means for permitting any ture of open rings, can be conveniently sprung. In this case, the lirst ring would be provided with a downwardly extending offset designed to be grounded on the cas- In the modified form illustrated in Fig. 7 of the drawings, I have shown the electrodes in the nature of steel washers 20 properly insulated from the central electrode 9, by means of washers 21 made from suitable insulating material, and in Fig. 8, another modified form, I have shown the electrodes in the form of a plurality of pins or studs "22, conveniently secured and arranged on the outside of thel insulating core, in any well known manner.

It will thus be seen that with a plug made in accordancewith my invention, I am enabled, firstly, to get a more intense spark because of the employment of a series of electrodes which are mounted upon the insulating core. Secondly, I am enabled to ignite weaker mixtures and thus get increased motor efficiency, because of the increased intensity of the spark.- Thirdly, short circuiting-r is absolutely overcome, by arranging the electrodes in series and insulating them from each other, it being readily understood that if one spark gap should be short-circuited, the resistance in the circuit would be immediately lowered, and the resulting4 sparks at the remainin gaps would only be intensied; and fourt ily, in the construction of my plug, it becomes unnecessary to take the same apart for adjusting the gaps, since, if the metal is burned away by the action of the electrical current wat one..point of the rings, the sparks will i Mb Said l claim:

, 1. A spark plug comprising an insulatin body reduced at its lower end, a chambered casin surrounding the reduced portion of gbody, a central electrode extending through said insulating body, a number of `electrodes consisting of open rings secured to the reduced portion'o the insulating body insulated from each other and from the central electrodes so as to form a series of aps, ,all electrodes secured to the outside o the reduced portion of the insulatin body having theirsparking surfaces Witlnn the chamber of said casing.

2. vA spark plug comprisin an insulating body reduced at its lower en a chambered casing surrounding the reduced portion of said body, a central electrode provided With an enlarged head extending through said innevate? V sulating body, a number of electrodes consistlng of open rings secured to the reduced portion of the insulating .body insulatedA from ,each other and from the central electrode so as to lform a series ol' gaps, all electrodes secured to the outside ofthe reduced portion of the insulating body having their sparking surfaces Withln the chamber of said easing, said chambered casing surrounding said electrodes and inclosing the same, and a Washer' provided with projections interposed between said insulating body and the enlarged head of the central electrode.

rlhis "specification signed and ,witnessed this seventh day of November, 1913.

i WALTER REPPIN; Witnesses:

ARTHUR H. MAGUIRE, FREDK C. FISCHER. 

